/*
 * Crypto wrapper for Microsoft CryptoAPI
 * Copyright (c) 2005-2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"
#include <windows.h>
#include <wincrypt.h>

#include "common.h"
#include "crypto.h"

#ifndef MS_ENH_RSA_AES_PROV
#ifdef UNICODE
#define MS_ENH_RSA_AES_PROV \
    L"Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)"
#else
#define MS_ENH_RSA_AES_PROV \
    "Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)"
#endif
#endif /* MS_ENH_RSA_AES_PROV */

#ifndef CALG_HMAC
#define CALG_HMAC (ALG_CLASS_HASH | ALG_TYPE_ANY | ALG_SID_HMAC)
#endif

#ifdef __MINGW32_VERSION
/*
 * MinGW does not yet include all the needed definitions for CryptoAPI, so
 * define here whatever extra is needed.
 */

    static BOOL WINAPI
(*CryptImportPublicKeyInfo)(HCRYPTPROV hCryptProv, DWORD dwCertEncodingType,
        PCERT_PUBLIC_KEY_INFO pInfo, HCRYPTKEY *phKey)
    = NULL; /* to be loaded from crypt32.dll */


static int mingw_load_crypto_func(void)
{
    HINSTANCE dll;

    /* MinGW does not yet have full CryptoAPI support, so load the needed
     * function here. */

    if (CryptImportPublicKeyInfo)
        return 0;

    dll = LoadLibrary("crypt32");
    if (dll == NULL) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: Could not load crypt32 "
                "library");
        return -1;
    }

    CryptImportPublicKeyInfo = GetProcAddress(
            dll, "CryptImportPublicKeyInfo");
    if (CryptImportPublicKeyInfo == NULL) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: Could not get "
                "CryptImportPublicKeyInfo() address from "
                "crypt32 library");
        return -1;
    }

    return 0;
}

#else /* __MINGW32_VERSION */

static int mingw_load_crypto_func(void)
{
    return 0;
}

#endif /* __MINGW32_VERSION */


static void cryptoapi_report_error(const char *msg)
{
    char *s, *pos;
    DWORD err = GetLastError();

    if (FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
                FORMAT_MESSAGE_FROM_SYSTEM,
                NULL, err, 0, (LPTSTR) &s, 0, NULL) == 0) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: %s: %d", msg, (int) err);
    }

    pos = s;
    while (*pos) {
        if (*pos == '\n' || *pos == '\r') {
            *pos = '\0';
            break;
        }
        pos++;
    }

    wpa_printf(MSG_DEBUG, "CryptoAPI: %s: %d: (%s)", msg, (int) err, s);
    LocalFree(s);
}


int cryptoapi_hash_vector(ALG_ID alg, size_t hash_len, size_t num_elem,
        const u8 *addr[], const size_t *len, u8 *mac)
{
    HCRYPTPROV prov;
    HCRYPTHASH hash;
    size_t i;
    DWORD hlen;
    int ret = 0;

    if (!CryptAcquireContext(&prov, NULL, NULL, PROV_RSA_FULL, 0)) {
        cryptoapi_report_error("CryptAcquireContext");
        return -1;
    }

    if (!CryptCreateHash(prov, alg, 0, 0, &hash)) {
        cryptoapi_report_error("CryptCreateHash");
        CryptReleaseContext(prov, 0);
        return -1;
    }

    for (i = 0; i < num_elem; i++) {
        if (!CryptHashData(hash, (BYTE *) addr[i], len[i], 0)) {
            cryptoapi_report_error("CryptHashData");
            CryptDestroyHash(hash);
            CryptReleaseContext(prov, 0);
        }
    }

    hlen = hash_len;
    if (!CryptGetHashParam(hash, HP_HASHVAL, mac, &hlen, 0)) {
        cryptoapi_report_error("CryptGetHashParam");
        ret = -1;
    }

    CryptDestroyHash(hash);
    CryptReleaseContext(prov, 0);

    return ret;
}


int md4_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
{
    return cryptoapi_hash_vector(CALG_MD4, 16, num_elem, addr, len, mac);
}


void des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
{
    u8 next, tmp;
    int i;
    HCRYPTPROV prov;
    HCRYPTKEY ckey;
    DWORD dlen;
    struct {
        BLOBHEADER hdr;
        DWORD len;
        BYTE key[8];
    } key_blob;
    DWORD mode = CRYPT_MODE_ECB;

    key_blob.hdr.bType = PLAINTEXTKEYBLOB;
    key_blob.hdr.bVersion = CUR_BLOB_VERSION;
    key_blob.hdr.reserved = 0;
    key_blob.hdr.aiKeyAlg = CALG_DES;
    key_blob.len = 8;

    /* Add parity bits to the key */
    next = 0;
    for (i = 0; i < 7; i++) {
        tmp = key[i];
        key_blob.key[i] = (tmp >> i) | next | 1;
        next = tmp << (7 - i);
    }
    key_blob.key[i] = next | 1;

    if (!CryptAcquireContext(&prov, NULL, MS_ENHANCED_PROV, PROV_RSA_FULL,
                CRYPT_VERIFYCONTEXT)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptAcquireContext failed: "
                "%d", (int) GetLastError());
        return;
    }

    if (!CryptImportKey(prov, (BYTE *) &key_blob, sizeof(key_blob), 0, 0,
                &ckey)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptImportKey failed: %d",
                (int) GetLastError());
        CryptReleaseContext(prov, 0);
        return;
    }

    if (!CryptSetKeyParam(ckey, KP_MODE, (BYTE *) &mode, 0)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptSetKeyParam(KP_MODE) "
                "failed: %d", (int) GetLastError());
        CryptDestroyKey(ckey);
        CryptReleaseContext(prov, 0);
        return;
    }

    os_memcpy(cypher, clear, 8);
    dlen = 8;
    if (!CryptEncrypt(ckey, 0, FALSE, 0, cypher, &dlen, 8)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptEncrypt failed: %d",
                (int) GetLastError());
        os_memset(cypher, 0, 8);
    }

    CryptDestroyKey(ckey);
    CryptReleaseContext(prov, 0);
}


int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
{
    return cryptoapi_hash_vector(CALG_MD5, 16, num_elem, addr, len, mac);
}


int sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
{
    return cryptoapi_hash_vector(CALG_SHA, 20, num_elem, addr, len, mac);
}


struct aes_context {
    HCRYPTPROV prov;
    HCRYPTKEY ckey;
};


void * aes_encrypt_init(const u8 *key, size_t len)
{
    struct aes_context *akey;
    struct {
        BLOBHEADER hdr;
        DWORD len;
        BYTE key[16];
    } key_blob;
    DWORD mode = CRYPT_MODE_ECB;

    if (len != 16)
        return NULL;

    key_blob.hdr.bType = PLAINTEXTKEYBLOB;
    key_blob.hdr.bVersion = CUR_BLOB_VERSION;
    key_blob.hdr.reserved = 0;
    key_blob.hdr.aiKeyAlg = CALG_AES_128;
    key_blob.len = len;
    os_memcpy(key_blob.key, key, len);

    akey = os_zalloc(sizeof(*akey));
    if (akey == NULL)
        return NULL;

    if (!CryptAcquireContext(&akey->prov, NULL,
                MS_ENH_RSA_AES_PROV, PROV_RSA_AES,
                CRYPT_VERIFYCONTEXT)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptAcquireContext failed: "
                "%d", (int) GetLastError());
        os_free(akey);
        return NULL;
    }

    if (!CryptImportKey(akey->prov, (BYTE *) &key_blob, sizeof(key_blob),
                0, 0, &akey->ckey)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptImportKey failed: %d",
                (int) GetLastError());
        CryptReleaseContext(akey->prov, 0);
        os_free(akey);
        return NULL;
    }

    if (!CryptSetKeyParam(akey->ckey, KP_MODE, (BYTE *) &mode, 0)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptSetKeyParam(KP_MODE) "
                "failed: %d", (int) GetLastError());
        CryptDestroyKey(akey->ckey);
        CryptReleaseContext(akey->prov, 0);
        os_free(akey);
        return NULL;
    }

    return akey;
}


void aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
{
    struct aes_context *akey = ctx;
    DWORD dlen;

    os_memcpy(crypt, plain, 16);
    dlen = 16;
    if (!CryptEncrypt(akey->ckey, 0, FALSE, 0, crypt, &dlen, 16)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptEncrypt failed: %d",
                (int) GetLastError());
        os_memset(crypt, 0, 16);
    }
}


void aes_encrypt_deinit(void *ctx)
{
    struct aes_context *akey = ctx;
    if (akey) {
        CryptDestroyKey(akey->ckey);
        CryptReleaseContext(akey->prov, 0);
        os_free(akey);
    }
}


void * aes_decrypt_init(const u8 *key, size_t len)
{
    return aes_encrypt_init(key, len);
}


void aes_decrypt(void *ctx, const u8 *crypt, u8 *plain)
{
    struct aes_context *akey = ctx;
    DWORD dlen;

    os_memcpy(plain, crypt, 16);
    dlen = 16;

    if (!CryptDecrypt(akey->ckey, 0, FALSE, 0, plain, &dlen)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: CryptDecrypt failed: %d",
                (int) GetLastError());
    }
}


void aes_decrypt_deinit(void *ctx)
{
    aes_encrypt_deinit(ctx);
}


struct crypto_hash {
    enum crypto_hash_alg alg;
    int error;
    HCRYPTPROV prov;
    HCRYPTHASH hash;
    HCRYPTKEY key;
};

struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
        size_t key_len)
{
    struct crypto_hash *ctx;
    ALG_ID calg;
    struct {
        BLOBHEADER hdr;
        DWORD len;
        BYTE key[32];
    } key_blob;

    os_memset(&key_blob, 0, sizeof(key_blob));
    switch (alg) {
        case CRYPTO_HASH_ALG_MD5:
            calg = CALG_MD5;
            break;
        case CRYPTO_HASH_ALG_SHA1:
            calg = CALG_SHA;
            break;
        case CRYPTO_HASH_ALG_HMAC_MD5:
        case CRYPTO_HASH_ALG_HMAC_SHA1:
            calg = CALG_HMAC;
            key_blob.hdr.bType = PLAINTEXTKEYBLOB;
            key_blob.hdr.bVersion = CUR_BLOB_VERSION;
            key_blob.hdr.reserved = 0;
            /*
             * Note: RC2 is not really used, but that can be used to
             * import HMAC keys of up to 16 byte long.
             * CRYPT_IPSEC_HMAC_KEY flag for CryptImportKey() is needed to
             * be able to import longer keys (HMAC-SHA1 uses 20-byte key).
             */
            key_blob.hdr.aiKeyAlg = CALG_RC2;
            key_blob.len = key_len;
            if (key_len > sizeof(key_blob.key))
                return NULL;
            os_memcpy(key_blob.key, key, key_len);
            break;
        default:
            return NULL;
    }

    ctx = os_zalloc(sizeof(*ctx));
    if (ctx == NULL)
        return NULL;

    ctx->alg = alg;

    if (!CryptAcquireContext(&ctx->prov, NULL, NULL, PROV_RSA_FULL, 0)) {
        cryptoapi_report_error("CryptAcquireContext");
        os_free(ctx);
        return NULL;
    }

    if (calg == CALG_HMAC) {
#ifndef CRYPT_IPSEC_HMAC_KEY
#define CRYPT_IPSEC_HMAC_KEY 0x00000100
#endif
        if (!CryptImportKey(ctx->prov, (BYTE *) &key_blob,
                    sizeof(key_blob), 0, CRYPT_IPSEC_HMAC_KEY,
                    &ctx->key)) {
            cryptoapi_report_error("CryptImportKey");
            CryptReleaseContext(ctx->prov, 0);
            os_free(ctx);
            return NULL;
        }
    }

    if (!CryptCreateHash(ctx->prov, calg, ctx->key, 0, &ctx->hash)) {
        cryptoapi_report_error("CryptCreateHash");
        CryptReleaseContext(ctx->prov, 0);
        os_free(ctx);
        return NULL;
    }

    if (calg == CALG_HMAC) {
        HMAC_INFO info;
        os_memset(&info, 0, sizeof(info));
        switch (alg) {
            case CRYPTO_HASH_ALG_HMAC_MD5:
                info.HashAlgid = CALG_MD5;
                break;
            case CRYPTO_HASH_ALG_HMAC_SHA1:
                info.HashAlgid = CALG_SHA;
                break;
            default:
                /* unreachable */
                break;
        }

        if (!CryptSetHashParam(ctx->hash, HP_HMAC_INFO, (BYTE *) &info,
                    0)) {
            cryptoapi_report_error("CryptSetHashParam");
            CryptDestroyHash(ctx->hash);
            CryptReleaseContext(ctx->prov, 0);
            os_free(ctx);
            return NULL;
        }
    }

    return ctx;
}


void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len)
{
    if (ctx == NULL || ctx->error)
        return;

    if (!CryptHashData(ctx->hash, (BYTE *) data, len, 0)) {
        cryptoapi_report_error("CryptHashData");
        ctx->error = 1;
    }
}


int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
{
    int ret = 0;
    DWORD hlen;

    if (ctx == NULL)
        return -2;

    if (mac == NULL || len == NULL)
        goto done;

    if (ctx->error) {
        ret = -2;
        goto done;
    }

    hlen = *len;
    if (!CryptGetHashParam(ctx->hash, HP_HASHVAL, mac, &hlen, 0)) {
        cryptoapi_report_error("CryptGetHashParam");
        ret = -2;
    }
    *len = hlen;

done:
    if (ctx->alg == CRYPTO_HASH_ALG_HMAC_SHA1 ||
            ctx->alg == CRYPTO_HASH_ALG_HMAC_MD5)
        CryptDestroyKey(ctx->key);

    os_free(ctx);

    return ret;
}


struct crypto_cipher {
    HCRYPTPROV prov;
    HCRYPTKEY key;
};


struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
        const u8 *iv, const u8 *key,
        size_t key_len)
{	
    struct crypto_cipher *ctx;
    struct {
        BLOBHEADER hdr;
        DWORD len;
        BYTE key[32];
    } key_blob;
    DWORD mode = CRYPT_MODE_CBC;

    key_blob.hdr.bType = PLAINTEXTKEYBLOB;
    key_blob.hdr.bVersion = CUR_BLOB_VERSION;
    key_blob.hdr.reserved = 0;
    key_blob.len = key_len;
    if (key_len > sizeof(key_blob.key))
        return NULL;
    os_memcpy(key_blob.key, key, key_len);

    switch (alg) {
        case CRYPTO_CIPHER_ALG_AES:
            if (key_len == 32)
                key_blob.hdr.aiKeyAlg = CALG_AES_256;
            else if (key_len == 24)
                key_blob.hdr.aiKeyAlg = CALG_AES_192;
            else
                key_blob.hdr.aiKeyAlg = CALG_AES_128;
            break;
        case CRYPTO_CIPHER_ALG_3DES:
            key_blob.hdr.aiKeyAlg = CALG_3DES;
            break;
        case CRYPTO_CIPHER_ALG_DES:
            key_blob.hdr.aiKeyAlg = CALG_DES;
            break;
        case CRYPTO_CIPHER_ALG_RC2:
            key_blob.hdr.aiKeyAlg = CALG_RC2;
            break;
        case CRYPTO_CIPHER_ALG_RC4:
            key_blob.hdr.aiKeyAlg = CALG_RC4;
            break;
        default:
            return NULL;
    }

    ctx = os_zalloc(sizeof(*ctx));
    if (ctx == NULL)
        return NULL;

    if (!CryptAcquireContext(&ctx->prov, NULL, MS_ENH_RSA_AES_PROV,
                PROV_RSA_AES, CRYPT_VERIFYCONTEXT)) {
        cryptoapi_report_error("CryptAcquireContext");
        goto fail1;
    }

    if (!CryptImportKey(ctx->prov, (BYTE *) &key_blob,
                sizeof(key_blob), 0, 0, &ctx->key)) {
        cryptoapi_report_error("CryptImportKey");
        goto fail2;
    }

    if (!CryptSetKeyParam(ctx->key, KP_MODE, (BYTE *) &mode, 0)) {
        cryptoapi_report_error("CryptSetKeyParam(KP_MODE)");
        goto fail3;
    }

    if (iv && !CryptSetKeyParam(ctx->key, KP_IV, (BYTE *) iv, 0)) {
        cryptoapi_report_error("CryptSetKeyParam(KP_IV)");
        goto fail3;
    }

    return ctx;

fail3:
    CryptDestroyKey(ctx->key);
fail2:
    CryptReleaseContext(ctx->prov, 0);
fail1:
    os_free(ctx);
    return NULL;
}


int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
        u8 *crypt, size_t len)
{
    DWORD dlen;

    os_memcpy(crypt, plain, len);
    dlen = len;
    if (!CryptEncrypt(ctx->key, 0, FALSE, 0, crypt, &dlen, len)) {
        cryptoapi_report_error("CryptEncrypt");
        os_memset(crypt, 0, len);
        return -1;
    }

    return 0;
}


int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
        u8 *plain, size_t len)
{
    DWORD dlen;

    os_memcpy(plain, crypt, len);
    dlen = len;
    if (!CryptDecrypt(ctx->key, 0, FALSE, 0, plain, &dlen)) {
        cryptoapi_report_error("CryptDecrypt");
        return -1;
    }

    return 0;
}


void crypto_cipher_deinit(struct crypto_cipher *ctx)
{
    CryptDestroyKey(ctx->key);
    CryptReleaseContext(ctx->prov, 0);
    os_free(ctx);
}


struct crypto_public_key {
    HCRYPTPROV prov;
    HCRYPTKEY rsa;
};

struct crypto_private_key {
    HCRYPTPROV prov;
    HCRYPTKEY rsa;
};


struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len)
{
    /* Use crypto_public_key_from_cert() instead. */
    return NULL;
}


struct crypto_private_key * crypto_private_key_import(const u8 *key,
        size_t len,
        const char *passwd)
{
    /* TODO */
    return NULL;
}


struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf,
        size_t len)
{
    struct crypto_public_key *pk;
    PCCERT_CONTEXT cc;

    pk = os_zalloc(sizeof(*pk));
    if (pk == NULL)
        return NULL;

    cc = CertCreateCertificateContext(X509_ASN_ENCODING |
            PKCS_7_ASN_ENCODING, buf, len);
    if (!cc) {
        cryptoapi_report_error("CryptCreateCertificateContext");
        os_free(pk);
        return NULL;
    }

    if (!CryptAcquireContext(&pk->prov, NULL, MS_DEF_PROV, PROV_RSA_FULL,
                0)) {
        cryptoapi_report_error("CryptAcquireContext");
        os_free(pk);
        CertFreeCertificateContext(cc);
        return NULL;
    }

    if (!CryptImportPublicKeyInfo(pk->prov, X509_ASN_ENCODING |
                PKCS_7_ASN_ENCODING,
                &cc->pCertInfo->SubjectPublicKeyInfo,
                &pk->rsa)) {
        cryptoapi_report_error("CryptImportPublicKeyInfo");
        CryptReleaseContext(pk->prov, 0);
        os_free(pk);
        CertFreeCertificateContext(cc);
        return NULL;
    }

    CertFreeCertificateContext(cc);

    return pk;
}


int crypto_public_key_encrypt_pkcs1_v15(struct crypto_public_key *key,
        const u8 *in, size_t inlen,
        u8 *out, size_t *outlen)
{
    DWORD clen;
    u8 *tmp;
    size_t i;

    if (*outlen < inlen)
        return -1;
    tmp = malloc(*outlen);
    if (tmp == NULL)
        return -1;

    os_memcpy(tmp, in, inlen);
    clen = inlen;
    if (!CryptEncrypt(key->rsa, 0, TRUE, 0, tmp, &clen, *outlen)) {
        wpa_printf(MSG_DEBUG, "CryptoAPI: Failed to encrypt using "
                "public key: %d", (int) GetLastError());
        os_free(tmp);
        return -1;
    }

    *outlen = clen;

    /* Reverse the output */
    for (i = 0; i < *outlen; i++)
        out[i] = tmp[*outlen - 1 - i];

    os_free(tmp);

    return 0;
}


int crypto_private_key_sign_pkcs1(struct crypto_private_key *key,
        const u8 *in, size_t inlen,
        u8 *out, size_t *outlen)
{
    /* TODO */
    return -1;
}


void crypto_public_key_free(struct crypto_public_key *key)
{
    if (key) {
        CryptDestroyKey(key->rsa);
        CryptReleaseContext(key->prov, 0);
        os_free(key);
    }
}


void crypto_private_key_free(struct crypto_private_key *key)
{
    if (key) {
        CryptDestroyKey(key->rsa);
        CryptReleaseContext(key->prov, 0);
        os_free(key);
    }
}


int crypto_global_init(void)
{
    return mingw_load_crypto_func();
}


void crypto_global_deinit(void)
{
}


int crypto_mod_exp(const u8 *base, size_t base_len,
        const u8 *power, size_t power_len,
        const u8 *modulus, size_t modulus_len,
        u8 *result, size_t *result_len)
{
    /* TODO */
    return -1;
}
